Electric motor.



R. E. BARKER.

ELECTRIC MOTOR.

APPLICATION FILED ooT. 14,1907.

91 9,523, Patented Apr. 27, 1909.

2 SHEETS-SHEET 1.

Fig I.

*jii 6 .5

I: I": v .5.

Witnesses I nv eniaor, WQ 6701 h E. Bal -Ker,

Raip y M awa R E. BARKER. ELECTRIC MOTOR.

APPLIOATION FILED 00w. 14,1907.

PatentedApr.27,1909.

2 SHEETSSHEET 2.

z Inventor, E.E ar"Ker',

Ralph Witnesses- WQWO UNITED s'r-A'rns PATENT OFFICE.

RALPH EIBARKER, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY,

' A CORPORATION OF NEW YORK.

arnc'raic MOTOR.

Specification of Letters Patent.

Application filed October 14, 1907.

Patented hpril 27, 1909.

Serial N0. 397,272.

To all whom it may concern:

Be it known that I, RALPH. E. BARKER, a citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful improvements in Electric Motors, of which the following isa specification.

My 'inventionrelates to electric motors, and particularly to single-phase induction motors. Motors of this type have no starting torque, unless special means are provided for producing it. It is therefore common practice to provide a starting circuit which isopened as soon as the motor is up to speed. Even when such a starting circuit is provided, the starting torque is small especially when the armature is of the squirrel cage type Without starting resistance. Consequently, such motors, especially in small sizes, are often arranged with the armature loosely mounted on tl1e shaft, and with a clutch, automatic or otherwise, for connecting'the armature to the shaft when the armature is up to speed. By means of this combination the armature may start freely, and is not loaded until it'is up to speed; at which time the torque is much greater than at starting.

While a starting switch and clutch have both been employed heretofore in single motors, these two devices have, so far as I know, been entirely independent of each other. 4

My invention consists in providing a single centrifugal device and operative connections therefrom to both the controlling switch and the clutch, so that automatic operation of both is obtained without the necessity of employingmore than one centrifugal device.

My inventlon Wlll best be understood by reference to the accompanying drawings, in

Y which Figure 1 shows a cross-sectional side elevation of a single-phase motor arranged in accordance with my invention; 2 shows an end-elevation of the motor-armature in partial cross-section on the line 2 2 of Fig. 4; Fig. 3 shows a detail view of the controlling switch for the starting circuit; Fig.

.4 shows a detail cross-sectional view on the line 4 4 of Fig. 2; and Fig. 5 is a diagram of the motor circuits.

arranged to form a squirrel-cage winding of ordinary construction.

A7 represents a pin carried by the spider l on which are provided a pair of centrifugal weights 8. These weights, when thrown out by centrifugal force, expand the frictionring 9, bringing it into engagement with the inner surface of the clutch 10, which is fast to the shaft 3. The centrifugal weights, the expansible ring 9 and the member 16) form an automatic clutch for con- 'necting the armature to the shaft when the armature is up to speed. A spring 11 carried on the pin.12 presses the centrifugal weights together, and when the motor is at rest, holds them in the position shown in Fig. 2.

13 represents a pair of stationary collector rings, which are supported on the pins 1 carried in the motor frame. Contacts 15, shown in Figs. 3 and 4, bear on the rings 13 when the. armature is at rest, and form with the rings a controlling switch for the start ing circuit of the motor. The contacts 15 are carried on pins, 16, which, in turn, are supported by the centrifugal weights 8. When the weights are thrown apart by centrifugal force, the movement of the pins 16 lifts the contacts 15 from thecollector-rings 13 so as to open the starting circuit of the motor.

The circuit connections of the motor are shown in Fig. 5, in which 6 represents the squirrel-cage winding, 2* the main winding,

This core, I

and 2 the starting winding on the stator.

By means of the constructlon one centrifugal-device serves both to clutch described,

- motor, and operative connections between spider and the controlling switch on the parts here shown, but aim in the appended erative connections from said device to both the armature to the shaft and'to open the By the use of a central spider and the overhanging core, and by placing the clutch beneath the overhang on one side of the other side, acompact.construction is secured.

I do not desire to limit myself to the particular construction and arrangement of claims to cover all modifications which are within the scope of my invention.

What I claim new and desire to secure by Letters Patent of the United States, is:

1. In an electric motor, a shaft, an arma- V ture loosely mounted thereon, centrifugallyoperated means carried by the armature for clutching the armature to the shaft, contacts controlling the starting connections of the said centrifugally-operated means and said contacts.

2. In an electric motor, a shaft, an armature loosely mounted thereon, a clutch for connecting shaft and armature together, a controlling switch for the motor, a centrifugal device carried by the armature, and opsaid'clutch and said switch.

In an electric motor, ashaft, an armature loosely mounted thereon, a clutch for connecting shaft and armature together,

stationary contacts, contacts carried by the armature adapted to engage the stationary contacts, a centrifugal device, and operative connections from said device to both said clutch and the last mentioned contacts.

4. In an electric motor, a shaft, a spiderloosely mounted on said shaft, a laminated armature core carried by said spider and over hanging it on each side, a clutch on one side of the spider beneath the overhung core adapted. to connect the shaft and spider together, a controlling switch comprising stationary collector rings surrounding the shaft on the other side of the spider beneath said core and contacts carried by the spider adapted to engage said rings, a centrifugal device carried by the spider, and operative connections from said device to both ,said clutch and said contacts.

In witness whereof, I have hereunto set my hand this ninth day of October, 1907. RALPH E. BARKER. Witnesses:

JOHN A. MoMAnUs, J12, PHILIP F. HARRINGTON. 

